You bet your life

The award of damages for the loss of a chance has gradually spread from claims against solicitors for the misconduct of litigation or commercial transactions into claims against accountants, trademark agents, government departments and even sellers of crude oil. Until now, it has been unclear why damages may be awarded for the loss of a chance if the negligent defendant is a solicitor, but not if they are a doctor.

This issue reached the House of Lords in Gregg v Scott (2005). By three to two, the Lords decided not to introduce awards of damages for lost chances in clinical negligence cases. That raises two questions in relation to non-clinical cases. First, does the loss of a chance approach survive outside the clinical field? Second, if it does, what is the rationale for different rules in different areas of the law? Does the decision in Gregg mean that the loss of a chance doctrine should be changed or modified in claims for pure economic loss?Malcolm Gregg went to see his GP about a lump under his arm. The doctor thought that the lump was an innocuous collection of fatty tissues. In fact, it was cancerous. This was discovered a year later, when a different GP referred Gregg for tests. The first GP ought to have referred Gregg for tests at the outset. The question was what loss this negligence had caused.

Gregg argued that, if referred immediately, he would have had a 42 per cent chance of survival for more than 10 years, but that due to the year’s delay his prospect of surviving was reduced to 25 per cent. He claimed damages for the reduction in his chance of surviving from 42 per cent to 25 per cent.

Conventionally, a claimant suing for negligence must prove that, if it were not for the defendant’s negligence, they would not have suffered loss. This has to be proved on the balance of probabilities, so the claimant has to prove that there is at least a 51 per cent chance that, had there been no negligence, they would not have suffered the loss claimed. As a result of this, the trial judge rejected Gregg’s claim. He could not prove that, had there been no negligence, he would probably have survived. Gregg appealed on the basis that he should have been awarded damages for the reduction in his chance of survival. He therefore invited the House of Lords to hold that a claimant may recover damages in a clinical negligence claim for the reduction in their chance of surviving a potentially fatal disease.

The majority - Lords Hoffmann and Phillips and Baroness Hale - rejected this invitation, but for different reasons. Anyone who thinks assessing statistical evidence about lost chances is an easy task, and who does not have a Masters degree in statistics, should read Lord Phillips’ speech. He pointed out that there were a number of features of the statistical evidence that counsel and the Court of Appeal had missed. The simplest was that the longer Gregg survived, the greater were his chances of surviving for even longer. He had survived for five years by the time of the trial, and eight years until the hearing in the House of Lords. After eight years, his prospects of surviving were much greater than at trial, and possibly greater than they would have been had there been no negligence. In addition, he stated that the statistical evidence did not support the contention that the negligence had caused a reduction from 42 per cent to 25 per cent in Gregg’s chances of survival. It was impossible to determine whether the negligence had caused any reduction in his chances of survival at all.

Lord Phillips concluded that there should be no award for the loss of a chance of survival from a fatal disease in cases where the adverse event (death) had not yet occurred. Claimants in these cases must prove their claim on the balance of probabilities. This was because of the difficulties in assessing causation and the lost chance. He left open the possibility that, in cases where the adverse event had actually been suffered, there might be a claim for the loss of a chance of cure.

Underlying Lords Phillips’ speech is a concern that Gregg might have been compensated for a reduction in his chances of survival even though he might survive into his nineties, or a proper analysis of the statistics might show that the negligence caused no reduction in his chances of survival.

Lord Phillips did not consider non-clinical loss of a chance cases. It is suggested that there is nothing in the speech that suggests those cases were decided incorrectly. Those cases mostly turn on the chances of human beings taking conscious decisions, which are probably not susceptible to Phillips’ style of analysis. Nevertheless, those advancing such arguments in non-clinical cases may wish to reflect on whether they have understood correctly the interplay of different chances and events occurring.

Baroness Hale and Lord Hoffmann did consider the non-clinical lost chance cases. It looks from their speeches as if they did not consider them wrongly decided. It is suggested that, contrary to the fears of some, the existing non-clinical lost chance cases are not overruled by Gregg.

So why are damages for lost chances recoverable in claims for pure economic loss, but not in clinical cases? One answer is that the non-clinical cases generally turn on the issue of what human beings would have done, rather than medical causation, and that it is easier to apply percentage chances to the former. But this view has to explain why the lost chance approach does apply to the actions of third parties but not to the actions of the claimant.

Lord Hoffmann’s answer is that this is a matter of policy. In theory, it is easier for a claimant to prove what they would have done than what a third party would have done. Another answer is that claims for pure financial loss are in a different category to claims for physical injury. But this would seem unfair to a person who was able to prove convincingly that negligence had caused a reduction in their chances of survival. A third answer is that the law assumes that causation by natural forces is always capable of proof, and so must be proved on the balance of probabilities, but that it is harder to prove what human beings would have done, so that the lost chance approach applies. But this theory cannot explain the rule that the claimant must prove what they would have done on the balance of probabilities. Happily for litigators, the debate about the rationale of lost chance cases goes on.

William Flenley is a barrister at Halisham Chambers.